Devices for the automatic detection of a fire are valuable because it is impossible for humans to be aware of their surroundings all of the time. Standard smoke detectors are known and can be one of several different types. For example, photoelectric smoke detectors are known that make use of a light beam and a light sensor capable of detecting the light beam. When smoke is not present, the light beam shines past the light sensor and does not contact the light sensor and the alarm is not activated. However, when smoke fills up a chamber through which the light beam travels, the light beam engages the smoke and is deflected or scattered some amount resulting in it engaging the sensor and being detected by the sensor. The alarm will then activate to warn people nearby of the presence of smoke, and hence fire. Other types of traditional smoke detectors utilize an ionization chamber and a source of ionizing radiation to detect smoke.
Fire detection devices are known that capture an image and then analyze the image in order to determine if flame is present in the image. One such device analyzes an image by looking at the intensity of the red, green, and blue color components of the image. Artificial light in the image is noted to exhibit only high luminance levels of the red component. These artificial sources of light may be tail lamps and headlights of vehicles. However, a flame that is present in the image will generate high luminance levels of both red and green components. In this manner, the fire detection device is able to analyze the color components of an image to determine if a flame is present, and to exclude other non-flame sources of illumination when detecting the fire.
A different fire detection device that makes use of image processing receives image data and then sends this image data to a fire detection module for detecting fire or signs of fire. Abstract information from the image such as texture, intensity, and color is evaluated. Object detection or segmentation is preferably not performed. The system uses a camera mounted onto the ceiling and has a field of view that extends along the ceiling but is not pointed downwards to the floor. A blinder or other blocking mechanism is used to prevent the camera from imaging the floor. This arrangement causes the system to focus only on the area of the ceiling where smoke will be detected, and to ignore movement on the floor that would otherwise confuse the system.
Additional fire detection systems have been proposed that seek to incorporate fire detection capabilities into a security system that uses imaging so that two separate systems, security and fire detection, can be combined into one for cost and utility savings. A beam of light is projected within the field of view of the camera, and changes in the light beam brought about by the presence of smoke will be detected by the system in order to alert the operator of the presence of fire.
There continues to be a need for devices that are capable of detecting the presence of fire and alerting people in order to provide them with adequate time to escape or put out the fire. Such a device should be mobile so that the user can take it with him or her when traveling and sleeping overnight in places that may or may not be equipped with smoke detectors. As such, there remains room for variation and improvement within the art.